May be off-topic but would anyone who's been in the forum long enough remembers or has encountered a post regarding in-Canada landing? Most of the popular threads involve flag-poling.
I only have one anecdotal experience to share: I accompanied my ex during her landing at the Vancouver CIC Offices, and they just stamped her passport, told her how long the PR card will take, that she needs to stay at least 2 years cumulative within 5 years (I'm guessing here, but I think this is what it was 2 years ago), and what date the earliest she can apply for citizenship (assuming she stays).
The thing is, I think it's really a better alternative for the OP to do it at CIC Offices rather than CBSA since the former will treat you like any other entrants. OP may be required to show the expired WP and this will generate questions.
@ PMM: If that's the case, then s/he can just sneak out of the country for a few days and land as-if s/he's just coming back. =P
@ Corrin: the OP already has a PR Visa, but has concerns landing since he suspects that he was out-of-status since July 2013.